23706

Appears in sequences

• a(n) = prime(n)*prime(n-1) - 1.at n=36A023515
• Number of unlabeled and connected graphs on n vertices which are chordal and P5-free.at n=9A079452
• Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=1, r=5, I={3,4}.at n=17A079958
• a(n) = (p-1)! mod p^2 where p = n-th prime.at n=36A112660
• Numbers k such that if you subtract k from its reversal you get a positive number with the same digits as k.at n=7A121970
• Let F(x) = 1 + 1*x + 4*x^2 + 10*x^3 + ..., the g.f. for A000293 (solid partitions), and write F(x) = 1/Product_{n>=1} E(n)^a(n) where E(n) = Product_{k>=n} (1 - x^(n*k)).at n=23A193718
• Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to zero or two horizontal or vertical neighbors.at n=11A199240
• Number of (w,x,y,z) with all terms in {1,...,n} and 2w*x<=3*y*z.at n=14A211921
• Total area of all trapezoids with bases p+q, q-p and height p*q with p,q prime, n = p+q and p < q.at n=35A335187